The present invention relates generally to post press printing equipment and more particularly to signature feeders and saddle conveyors.
U.S. Pat. No. 6,375,179 purportedly discloses a device for opening and depositing a folded signature onto a moving conveyor, particularly a collecting chain. The device includes two opening rollers with axes that extend essentially parallel to the conveying direction of the conveyor and respectively open one signature and deposit it with the opened side first in a downwardly direction onto the conveyor, wherein the signatures are pre-accelerated in the conveying direction of the conveyor.
U.S. Pat. No. 7,192,027 discloses a signature transport device which includes a first conveyor moving a plurality of folded signatures in a first direction and a second conveyor including a first blade having a first edge for lifting a first signature of the plurality of signatures from the first conveyor.
U.S. Pat. Nos. 7,530,564 and 7,631,914 and U.S. Publication No. 2008/0007075 A1 disclose a gripping device for gripping printed products. The gripping device includes a gripper having a first gripper arm having a first gripper pad on one end rotatable about a first pivot and a second gripper arm having a second gripper pad on one end rotatable about a second pivot.
U.S. Publication No. 2009/0309289 purportedly discloses an apparatus for withdrawing flat products from a stack and transporting the printed products. The apparatus includes a transporting device, a separating device and a rotating conveyor. The rotating conveyor includes at least one gripper with a gripper plane to grip a separated printed product in the gripper plane and supply the separated printed product to the transporting device.
FIG. 1 shows a conventional hopper apparatus 10. Hopper 10 includes a stack 12 of sheets or signatures which may be folded printed products. Each printed product is transported from a bottom of stack 12 to a gripper drum 20. As shown in FIG. 1, signature 14 is held onto gripper drum 20 via a gripper 22. Gripper drum 20 may include a plurality of grippers 22. As shown in FIG. 1, gripper drum 20 includes three grippers. A suction element 16 may aid the removal of the bottommost signature from stack 12. A spine of the folded signature is pulled down by suction element 16 then gripped by gripper 22 so the spine of signature 14 is tucked into gripper drum 20. Gripper drum 20 rotates in a counterclockwise direction until signatures 14 reaches a register stop 24. Register stop 24 provides a consistent location for lining up a lap in the tail open end of signature 14 for transfer to opening drums 30, 32. Signature 14 is then transported in a different direction via guide 26, with the tail open end of the folded signature now leading. Signature 14 is transported to opening rollers 30, 32, which open signature 14 by each gripping a leg of signature 14. Opening rollers 30, 32 open signatures 14 as the rollers 30, 32 rotate and drop signature 14 onto a saddle conveyor or collecting chain 40.